fix: AgentCore VPC validation and remove agentCoreNetworkType parameter

- Fix validation logic to properly handle null values for agentCoreSubnetIds
- Remove agentCoreNetworkType parameter (network mode is now auto-detected)
- Update documentation to reflect the simplified VPC configuration
- Add isAgentCoreNetworkPrivate computed property

Author: nakayukl-demo

docs/en/DEPLOY_OPTION.md

@@ -773,10 +773,12 @@ Network settings apply to both Generic Runtime and AgentBuilder Runtime.
 
 When using VPC mode, configure the following parameters:
 
-- `agentCoreNetworkType`: Set to `PRIVATE`
 - `agentCoreVpcId`: VPC ID to use
 - `agentCoreSubnetIds`: List of subnet IDs to use
 
+> [!NOTE]
+> When both `agentCoreVpcId` and `agentCoreSubnetIds` are configured, AgentCore Runtime will be deployed in private network mode. If both are left unset (`null`), it will be deployed in public network mode.
+
 > [!IMPORTANT]
 > **Availability Zone (AZ) Support**: AgentCore Runtime has limited supported AZs per region. Subnets must be placed within supported AZs. For details, please refer to the [AWS official documentation](https://docs.aws.amazon.com/bedrock-agentcore/latest/devguide/agentcore-vpc.html#agentcore-supported-azs).
 >
@@ -790,7 +792,6 @@ const envs: Record<string, Partial<StackInput>> = {
   dev: {
     createGenericAgentCoreRuntime: true,
     agentBuilderEnabled: true,
-    agentCoreNetworkType: 'PRIVATE',
     agentCoreVpcId: 'vpc-xxxxxxxxx',
     agentCoreSubnetIds: ['subnet-xxxxxxxxx', 'subnet-yyyyyyyyy'],
   },
@@ -805,7 +806,6 @@ const envs: Record<string, Partial<StackInput>> = {
   "context": {
     "createGenericAgentCoreRuntime": true,
     "agentBuilderEnabled": true,
-    "agentCoreNetworkType": "PRIVATE",
     "agentCoreVpcId": "vpc-xxxxxxxxx",
     "agentCoreSubnetIds": ["subnet-xxxxxxxxx", "subnet-yyyyyyyyy"]
   }

docs/ja/DEPLOY_OPTION.md

@@ -788,10 +788,12 @@ AgentCore Runtime は以下のネットワークモードで動作できます
 
 VPC モードを使用する場合は、以下のパラメータを設定してください：
 
-- `agentCoreNetworkType`: `PRIVATE` に設定
 - `agentCoreVpcId`: 使用するVPCのID
 - `agentCoreSubnetIds`: 使用するサブネットのIDリスト
 
+> [!NOTE]
+> `agentCoreVpcId`と`agentCoreSubnetIds`を両方設定すると、AgentCore Runtimeはプライベートネットワークモードでデプロイされます。両方とも未設定（`null`）の場合は、パブリックネットワークモードでデプロイされます。
+
 > [!IMPORTANT]
 > **Availability Zone (AZ) サポート**: AgentCore RuntimeはリージョンごとにサポートされているAZが限定されています。サブネットは必ずサポートされているAZ内に配置してください。詳細は[AWS公式ドキュメント](https://docs.aws.amazon.com/bedrock-agentcore/latest/devguide/agentcore-vpc.html#agentcore-supported-azs)をご確認ください。
 >
@@ -805,7 +807,6 @@ const envs: Record<string, Partial<StackInput>> = {
   dev: {
     createGenericAgentCoreRuntime: true,
     agentBuilderEnabled: true,
-    agentCoreNetworkType: 'PRIVATE',
     agentCoreVpcId: 'vpc-xxxxxxxxx',
     agentCoreSubnetIds: ['subnet-xxxxxxxxx', 'subnet-yyyyyyyyy'],
   },
@@ -820,7 +821,6 @@ const envs: Record<string, Partial<StackInput>> = {
   "context": {
     "createGenericAgentCoreRuntime": true,
     "agentBuilderEnabled": true,
-    "agentCoreNetworkType": "PRIVATE",
     "agentCoreVpcId": "vpc-xxxxxxxxx",
     "agentCoreSubnetIds": ["subnet-xxxxxxxxx", "subnet-yyyyyyyyy"]
   }

docs/ko/DEPLOY_OPTION.md

@@ -772,10 +772,12 @@ AgentCore Runtime은 다음 네트워크 모드에서 작동할 수 있습니다
 
 VPC 모드를 사용할 때는 다음 매개변수를 설정하세요:
 
-- `agentCoreNetworkType`: `PRIVATE`로 설정
 - `agentCoreVpcId`: 사용할 VPC ID
 - `agentCoreSubnetIds`: 사용할 서브넷 ID 목록
 
+> [!NOTE]
+> `agentCoreVpcId`와 `agentCoreSubnetIds`를 모두 설정하면 AgentCore Runtime이 프라이빗 네트워크 모드로 배포됩니다. 둘 다 미설정(`null`)인 경우 퍼블릭 네트워크 모드로 배포됩니다.
+
 > [!IMPORTANT]
 > **가용 영역(AZ) 지원**: AgentCore Runtime은 리전별로 지원되는 AZ가 제한되어 있습니다. 서브넷은 반드시 지원되는 AZ 내에 배치해야 합니다. 자세한 내용은 [AWS 공식 문서](https://docs.aws.amazon.com/bedrock-agentcore/latest/devguide/agentcore-vpc.html#agentcore-supported-azs)를 확인하세요.
 >
@@ -789,7 +791,6 @@ const envs: Record<string, Partial<StackInput>> = {
   dev: {
     createGenericAgentCoreRuntime: true,
     agentBuilderEnabled: true,
-    agentCoreNetworkType: 'PRIVATE',
     agentCoreVpcId: 'vpc-xxxxxxxxx',
     agentCoreSubnetIds: ['subnet-xxxxxxxxx', 'subnet-yyyyyyyyy'],
   },
@@ -804,7 +805,6 @@ const envs: Record<string, Partial<StackInput>> = {
   "context": {
     "createGenericAgentCoreRuntime": true,
     "agentBuilderEnabled": true,
-    "agentCoreNetworkType": "PRIVATE",
     "agentCoreVpcId": "vpc-xxxxxxxxx",
     "agentCoreSubnetIds": ["subnet-xxxxxxxxx", "subnet-yyyyyyyyy"]
   }

packages/cdk/lib/stack-input.ts

@@ -223,8 +223,9 @@ export const stackInputSchema = baseStackInputSchema
     (data) => {
       // Validate AgentCore VPC configuration consistency
       const hasVpcId = !!data.agentCoreVpcId;
-      const hasSubnetIds =
-        data.agentCoreSubnetIds && data.agentCoreSubnetIds.length > 0;
+      const hasSubnetIds = !!(
+        data.agentCoreSubnetIds && data.agentCoreSubnetIds.length > 0
+      );
 
       // Both must be provided or both must be empty
       return hasVpcId === hasSubnetIds;